Re: elaphe taxonomy

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: : the thread below about janseni got me thinking about the mess that is "elaphe". having kept or handled a variety of these : species, i know that they are a real mess (as does everyone else). i wish someone would tackle the systematics of the : group as a whole, though, instead of doing it piecemeal like dowling did when he elevated senticolis and bogertophis . . . : : here's my "gestalt" unsupported by evidence taxonomic groupings that i suspect are "real" : : N american "elaphe" - obsoleta, guttata, vulpina : These are closely related species. According to Burbink et al. (2000, Evolution) E. vulpina is the sister species of E. : obsoleta. According to Dowling et al. (1983, J. Zool.), the E. guttat-E. obsoleta split occurred in the Pliocene but the E. : obsoleta-Pituophis split is more recent. So the tree looks like this: : _____Elaphe obsoleta : ___ | : | |_____Pituophis : ____| : | | : | |_________ Elaphe guttata : | : | ___ Lampropeltis getulus : | __| : | | |___ Lampropeltis triangulum : | __| : | | |______ Cemophora coccinea : |_ __| : | __ Lampropeltis mexicana (alterna) : |______| : |__ Lampropeltis calligaster : Rhinocheilus, Arizona and Stilosoma are also part of this : North American ratsnake clade. North American Elaphe is therefore paraphyletic with respect to Lampropeltis, Cemophora, Pituophis, Rhinocheilus and Stilosoma. : : Eurasian "elaphe" - dione, quaturolineata, scalaris, schrenki, climacophora, and bimaculata in one group; longissima, : persica, situla, and hohenackeri in another : : "mandarina" group - mandarina, porphyracea, conspicillata : : "trinket" group - helenae, taeniura, radiata, frenata, prasina, hodgsoni : : "gonyosoma" - janseni, oxycephala (note the microdermatoglyphics of oxycephala are very different from radiata) : : "carinata" - carinata, quadrivittata : Lopez and Maxson (1995, Biochem. System. Ecol.), based on Mitochondrial DNA, found that the Eurasian ratsnakes are paraphyletic with respect to New World Elaphe and Lampropeltis, Pituophis et al. : Gonyosoma is NOT a ratsnake. It is a racer that has converged upon the ratsnakes. : : "american desert ratsnakes" - both bogertophis and senticolis - to me, these are very very similar animals, even though : senticolis is largely diurnal - flavirufra probably also goes with these snakes : These ratsnakes are also part of the North American ratsnake clade. : : odds and sods - davidi (who knows?), mollendorfi seems very different from other elaphe, although i guess it seems : closest to the large eurasian group, rufodorsata which just ain't even close! : : i know i've left out a few of the more obscure species, but thought i'd fish for comments on these arrangements. : : and does anyone know of their is a name already on the books that could be used if someone were to split the eurasian : and american "elaphe"? i know that the first member of the genus described was a quaturolineata, so the name "elaphe" : would stick with the european stuff. : Since I am not opposed to the recognition of paraphyletic taxa, I don't have to lose any sleep over the last question. :) In fact, it would create a pretty big mess if we were to eliminate paraphyly completely. Elaphe guttata and E. obsoleta, for example, could end up in different genera in order to completely eliminate paraphyly. And it is difficult to imagine what the diagnostic characters of those different genera could be.

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